The development of tire constructions which include an annular reinforcement belt, or breaker, about the periphery of the tire between the tread and the carcass has provided tires with better road stability and longer tread life in both radial and bias ply constructions. According to a preferred type of construction, shown for example in U.S. Pat. Nos. 3,720,569, 3,720,570, 3,729,365 and 3,770,042, one or more reinforcement strips are zig-zagged about a drum until a continuous reinforcement belt is woven. Each of the reinforcement strips is formed of a plurality of tire cords of suitable reinforcement material embedded in a coating material as described, for example, in U.S. Pat. No. 3,737,262. Unfortunately, as described above, the presence of knots or other enlargements in the tire cord cause interruptions in the process with too great a frequency.
In U.S. Pat. No. 4,308,823, Klein discloses an apparatus which is said to permit the improved coating of cords which have knots or other enlargements in them. According to that disclosure, an apparatus is suggested which detects the presence of knots and then causes an increase in the effective size of the entrance into the coating chamber responsive to the presence of the knots. The disclosed apparatus is, however, quite complicated mechanically, making it expensive to construct and maintain.
There is a present need for an apparatus of simplified construction which will permit the passage of cord having knots or other enlargements into an extrusion coating chamber.